1. Field of the Invention
The present invention relates generally to the field of computer software security systems, and, more particularly, the present invention relates to a digital compact disc player security system wherein security code information is stored on a digital optical compact disc through modulating an offset of the physical position of a plurality of optically encoded data bits on the disc from a nominal track position in order to ensure that a disc player system is exclusively used with authorized software containing a predetermined security code.
2. Description of the Related Art
Recently in the field of data storage and retrieval, the use of optical compact discs has grown significantly. Digital optical storage devices have the advantage of having a large storage capacity compared with other forms of data storage. In these systems it is often desirable to protect a dedicated player system from being used with unauthorized software. This is especially true in the video game market where video game manufacturers typically sell game playing devices at or near their cost with the expectation that sales and royalties on the software for the games will provide a large return.
Conventional systems for protecting devices which are capable of operating with a variety of computer software typically employ a security code to protect the system from being used with unauthorized computer software. In a conventional system for preventing a dedicated disc reproducing apparatus from being used with unauthorized software, the system initially determines whether a security code is present at a predetermined memory location of the storage medium which contains the software. The player or reproducing apparatus determines whether or not the software is authorized by comparing the data stored in the predetermined memory location with a security code. This is generally known as a security system or protect processing.
In recent years there has been a number of instances where even systems which have protect processing or security systems have been subject to use with unauthorized computer software. There have been instances where the protect processing has been illegally avoided even with the security system as described above. One reason for this is that in conventional security systems the security code is located in a predetermined memory location which can be readily identified by examining the software. This is also at least partially due to the fact that the determination as to whether or not this recording medium is authorized and execution of the computer program are carried out by the same hardware. The present invention addresses these problems and overcomes the shortcomings of the prior art.